1. The Field of the Invention
The present invention is generally related to optical transceiver modules employed in optical communications networks. More specifically, the present invention is related to an adjustable optical transceiver design that maximizes thermal dissipation from heat-sensitive transceiver components.
2. The Related Technology
Fiber optic technology is increasingly employed as a method by which information can be reliably transmitted via a communications network. Networks employing fiber optic technology are known as optical communications networks, and are marked by high bandwidth and reliable, high-speed data transmission.
Optical communications networks employ optical transceivers in transmitting information via the network from a transmission node to a reception node. An optical transceiver at the transmission node receives an electrical signal (containing digital information or other data) from a network device, such as a computer, and converts the electrical signal via a laser to a modulated optical signal. The optical signal can then be transmitted in a fiber optic cable via the optical communications network to a reception node of the network. Upon receipt by the reception node, the optical signal is fed to another optical transceiver that uses a photodetector to convert the optical signal back into electrical signals. The electrical signals are then forwarded to a host device, such as a computer, for processing. The optical transceivers described above have both signal transmission and reception capabilities; thus, the transmitter portion of a transceiver converts an incoming electrical signal into an optical signal, whereas the receiver portion of the transceiver converts an incoming optical signal into an electrical signal.
In addition to the laser and photodetector mentioned above, several other components are also internally included within a typical transceiver module. Among these are a controller, which governs general operation of the transceiver, a laser driver for controlling operation of the laser in the transmitter portion, and a post-amplifier for controlling the photodetector that converts incoming optical signals into electrical signals in the receiver portion.
In a typical transceiver, the components responsible for transmitting and receiving optical signals are located in a transmitting optical sub assembly (“TOSA”) and a receiving optical sub assembly (“ROSA”), respectively. Specifically, the laser and associated components for producing an optical signal are located in the TOSA, while the photodetector and related components for receiving an optical signal are located in the ROSA.
Because excessive temperatures can adversely affect the operation of the TOSA and ROSA, it is important to provide adequate means by which heat can be reliably removed from these and similar transceiver assemblies. Specifically, it is desirable to remove heat from within the assembly itself, this heat having been produced by internal assembly components. For example, the laser that is located within the TOSA produces relatively large amounts of heat that, if not removed, can result in malfunction of one or more assembly components.
Unfortunately, many challenges have arisen in attempting to provide adequate heat dissipation from optical transceiver assemblies, such as the TOSA and the ROSA. Many of these challenges center around the difficulty in transferring the heat that is produced inside the TOSA subassembly or ROSA which typically include hermetically sealed housings containing the transmitting or receiving components to heat sinks outside the subassembly. As already mentioned, excess heat buildup within the TOSA, ROSA, or similar housing can result in malfunctioning of the transceiver module and interruption of optical communications.
Of particular concern in the art has been the provision of an adequate heat path from within a TOSA to the outer housing of the transceiver, which serves as a sink for heat generated by the laser and other components located within the TOSA. Because of necessary alignment procedures that are performed on the TOSA during transceiver assembly in order to align its various optical components, a dimensional variability in the optical transceiver is introduced, causing the distance between the TOSA and the outer housing to potentially change according to the desired alignment. Moreover, because the desired alignment of TOSA optical components varies with each optical transceiver that is assembled, the distance between the TOSA and an outer transceiver housing can likewise vary from transceiver to transceiver. This variability substantially prevents the use of stock heat dissipating components, which in turn hinders the ability to establish an adequate heat path between the TOSA and the transceiver housing. Similar problems can also exist with the ROSA and with other transceiver components.
One attempt to overcome the above difficulties has involved custom fitting each optical transceiver with proper sized heat dissipating components. While this approach has been successful at removing heat from the TOSA during transceiver operation, it also represents a significant cost in terms of time and manpower resources to the extent that it becomes cost-prohibitive in practice.
Another approach that has been attempted in overcoming the above difficulties has involved the use of compliant materials to establish a thermal path between the TOSA and the transceiver housing. This approach, however, suffers from the compliant material's lack of adequate heat transfer efficiency, thereby preventing sufficient heat dissipation from the TOSA.
In light of the above discussion, a need currently exists for an optical transceiver that benefits from enhanced heat dissipation characteristics. In particular, there is a need for a system and method by which heat produced within the optical subassemblies of a transceiver can be reliably dissipated, thereby ensuring proper operation of the transceiver.